The Chicago Board of Trade's acquisition by Chicago Mercantile Exchange is moving forward after antitrust clearance, but IntercontintentalExchange has not given up. It revised its bid, already about $1.1 billion more than CME's, to give CBOT shareholders an oppotunity to receive cash instead of stock and said it would file proxy materials opposing CME's acquisition. See NYTimes, Suitor Revises Bid for Chicago Board; WSJ, IntercontinentalExchange Upgrades Its Bid for CBOT.